Topical Area: Dietary Bioactive Components
Ocimum is a genus of aromatic, annual and perennial herbs and shrubs, in the family Lamiaceae, native in Asia, Africa, South, and Central America. Ocimum includes about 150 species; of which the most well- known and widely used for culinary purposes is O. basilicum (basil). Ocimum species have been reported to exhibit anti-diabetic property. The objective of this study was to analyze Ocimum species for antidiabetic properties and identify compound(s) that may be best associated with its anti-hyperglycemic effects.
Methods : Sixteen Ocimum accessions consisting of three O.africanum, two O.americanum, four O. basilicum, one O.campechianum, two O.gratissimum, and three O.tenuiflorum accessions were cultivated using organic production system. Leaves were harvested at peak vegetative phase, lyophilized, and ground into fine particles and extracted with aqueous methanol.
Results : A primary evaluation of phytochemicals demonstrated the presence of eugenol, β-sitosterol, caffeic acid, chicoric acid, luteolin, oleanolic acid, rosmarinic acid, and ursolic acid in Ocimum species. Analysis of the crude extracts of the above 16 Ocimum accessions showed that O.tenuiflorum, O.gratissimum, and O.basilicum inhibited yeast alpha glucosidase activity. Of these, O.tenuiflorum demonstrated comparable IC50 inhibitory concentrations as acarbose, a widely-prescribed anti-diabetic medication. Additionally, further sub-fractionation of crude extracts retained and enhanced the alpha glucosidase inhibitory property, with O.tenuiflorum and O.gratissimum showing maximal inhibitory effects (60% - 70% inhibition) that were comparable to acarbose (75% inhibition).
Conclusions : These studies suggest anti-hyperglycemic potential of O.tenuiflorum and O.gratissimum species.
Funding Sources : NIFA-USDA